Duplicating with the aid of stencils



Patented Mar. 30, 1926.

UNITED STATES 1,579,079 PATENT -OF FICE.

JOHN CLATWORTHY, OF PLUMSTEAD, ENGLAND, ASSIGNOR TO D. GESTETNER,

LIMITED, 01: LONDON, ENGLAND.

DUPLICATING WITH THE AID 0F STENCILS.

No Drawing.

To all whom. it may concern:-

' Be it known that I, JoHN CLA'rwon'rHY, a British Subject, and residing at 109 Tuam Road, Pluinstead, in the county of Kent, England, have invented certain new and useful Improvementsin and Relating to Duplicating with the Aid of Stencils, of which the following is a specification.

This invention relates to duplicating drawings, manuscript and typewritten matter and the like with the aid of stencils cut by the employment of'a style or in a typewriter.

As is well known, in producing such stencils combined stencil sheetscomprising essentially a foraminous support, such as Yoshino paper, provided with what may be described as a stencil layer and a backing sheet formed of a somewhat rigid or hard surfaced non-absorbent paper, which in some cases is provided over the greater portlon of its surface with a coating of ordinary printing ink are employed.

When using a combined stencil sheet of this kind, even when the stencil layer contains a white pigment, the lines or characters cut in the stencillayer do not show up at all'clearly against the black or darkcoloured background.

The object of the present invention is to provide an improved combined stencil sheet which will enable the impressions formed in the stencil layer to be more legible.

The invention consists broadly in a combined stencil sheet having a hard-surfaced backing sheet coated on that portion of its surface which is in contact with the sheet adapted to be stencilized, with a composition containing a colouring,.matter adapted to be transferred to the stencil sheet where pressure is applied thereto by the means op erating to cut the stencil layer.

The colouring matter will be one which contrasts with the colour of the stencil layer; thus, it could be a white pigment if the stem cil layer-were dark in colour, while if the stencil layer is substantially white the colouring matter used would be dark in colour being, for instance, substantially black.

In this connection it may be remarked that the invention is mainly concerned with stencil sheets in which the stencil layer contains a white igment and therefore in its more restricts scope 1t may be stated to consist in a oomblned stencil sheet compris- Application filed March a, 1924. Serial no. 702,999.

ing a' sheet of foraminous material provided with a stencil layer 'containin an opa ue white pigment and a backing s eet there or consisting of a sheet of hard-surfaced paper, coated on that portion of its surface which is in contact with the foraminous material provided with the stencil layer with a composition containin a colouring matter adapted to be trans erred to the-stencil sheet where pressure is applied thereto by the means operating to cut the stencil layer.

The composition containing a colouring matter may be of any convenient character. It should, however, contain nothing which will operate to modify materially the prop- A sheet of stiff hard-surfaced paper is coated over a considerable portion of its surface with .a layer of an ink formed by grinding lamp-black and, if desired, a small proportion of Prussian blue, in mineral 'elly.

To aportion of the sheet thus treated, ad-

jacent to one edge thereof, a sheet; of Yoshino paper provided with a stencil layer is'con- 1 nected by. means of an adhesive,- a cover sheet being optionally secured in position over the stencil layer by means of an adhesive applied-over that portion of the sheet of Yoshino paper-which is connected with the'backing sheet.

As will be understood, the cil sheet in accordance with the invention presents considerable advantages-over the known combinations in connection with which is has been p-roposed to insert between the backing sheet and the stencil sheet a sheet of carbon paper, in that firstly the composition with which the sheet is coated resists or inhibits the tendency of the backing sheets to absorb the tempering agent from the composition of which the stencil layer is formed and thus operates to kee the; stencil in conditi n for use and, second combined sten-' ly, the time andtrouble involved in intro 7 ducing a sheet ofcarbon paper between the stencil sheet and backing sheet is saved.

Having now described my invention, what I claiinasnew and desire to secure by Let-, ters Patent is --1., A combined stencil sheet foruse in du- I plioating, comprising-a sheet adapted to be 'stencilized by pressureand a hard-surfaced m backing sheet coated on that portion of its surface which is in contact with the sheet adapted to -beistencilized,'with a composition containing 1 a colouring matter adapted to be transferred to the sheet where pressure isapplied thereto by" the meansoperating to cutthe'stencil layer.

7 '2; *A o bined stencil sheet for use in duplicatiomcomprising a sheet of ,foraminous material provided with a coating of a material adapted to be stencilized by pressure,

.and a sheet of hard-surfaced paper coated on that portion of its surface which is in contact with the sheet of foraminous material with a composition containing a colour- 5 ing'mat-ter adapted to be transferred to the stencil sheet where pressure is applied thereto by-- the means operating to cut the stencil layer.

backing sheet to change the properties of the coating of the sheet of foraminous materialand containing a colouring matteradapted to be transferred to the coated sheet of. foraminous material where pressure is applied thereto by the means operating to cut I the stencil.

'4. A combined stencil sheet'for use in duplicating, comprising a'sheet of material including -a tempering agent adapted to be stencili'zed by pressure, a hard-surfaced backing sheet detachabl'y connected therewith and a coating of a composition on the face of the backing sheet contacting with the sheet adaptedto be stencilized by pressure, said composition carryinga colouring 'matter and being adapted to be transferred to the last-mentioned sheet in the operation of stencilizing and including materials adapted to prevent the absorption of the tempering agent by the backing sheet.

' 5. A combined stencil sheet for use in duplicating, comprising a sheet of material including a tempering agent adapted to be ste-ncihzed by pressure, a hard-surfaced backing sheet detachably connected therewith and a coating of a composition on the face of the backing sheet contacting with the sheet adapted to be stencilized by pressure, said composition carrying a colouring matter and being adapted to be transferred to thelast-mentioned sheet in the operation of stencilizing, including materials adapted to prevent the absorption of the tempering agent by the backing sheet: and inert to the stencil composition.

In testimony whereof I have signedmy name to this specification.

JOHN CLATWORTHY. 

